MEM-S – Unlocking ancient secrets of the deep to extend the boundaries of modern biotech
In today's fast-moving world, many forms of human activity require ever more
precise and sophisticated technology – either to perform a particular, specialised
function, or to provide reliable means of micro-screening and analysis.
The rapidly evolving spheres of biotechnology and nanotechnology provide many of the required solutions. Frequently the two are combined - in the form of nanobiotechnology.
One area where demand for this technology is strong is that of membranes for microsieves – nanoscale filtration methods, which play a key role in the analytical systems, used in areas such as food processing, drug discovery or medical diagnostics. anoporous membranes and microsieves can be used to eliminate, or to detect the presence of microbes in drinking water, such as Legionella or E.coli. In the biomedical field, they can be used to detect tiny differences or abnormalities among cells.
They are even used as a way of ascertaining beer purity.
An unlikely but extremely fertile source of new discoveries and materials to assist with this technology is the seabed - in the cold zones where no light penetrates.
Life originated in the sea. The oldest animals still in existence are the sea sponges. And, incredibly, it is these animals, the most ancient form of life on earth, that are now making a vital contribution to the world's most modern science. This phenomenon is at the heart of Mem-S, a research project funded under the EU's 7th Framework Programme with the aim of using cutting-edge molecular biology techniques to design and fabricate nanoporous membranes and microsieves with new and innovative capabilities for use in industrial applications.
Begun in 2010, the three-year project, leaded by the University Medical Centre of the University of Mainz, involves three researchbased SMEs and four universities and research institutes from Germany, the Netherlands, Austria and France.
Sea sponges contain a number of enzymes and proteins. One of these is silicatein, the only known enzyme in existence with the capability of synthesising an inorganic polymer, silica, from an inorganic precursor molecule.
This silica (or biosilica) is what forms the sponge's skeleton. However, its key property combinations, including light transmission and extreme stability – unlike technical glass, which breaks easily – make it valuable for a range of advanced technological applications.
Just as importantly, the silicatein needed to form the silica can be produced in a sustainable way by a process of genetic engineering, inserting the sponge gene into bacteria.
In the Mem-S project, this breakthrough technology is linked with another cutting-edge development – so-called 'S-layer' (crystalline bacterial cell surface layer) technology. The beauty of S-layer proteins is that they assemble themselves in highly ordered structures of defined pore size and shape – a feature that makes them ideal for use as nanoporous membranes in microsieves.
By binding to the silica, enzymatically produced by the silicatein, the membrane gains reinforcement and support, while the silica can also be utilised to encase any specific biomolecules needed for the individual filtration or sensory function required.
The new technique will be exploited by the three SME's involved in the project – the German NanotecMARIN GmbH, and the Netherlands' Lionix BV and Aquamarijn Micro Filtration BV, in sensors in drinking water systems, in industrial nanosieves and in microfluidics-based sample processing and micro-array development.
The astounding properties of biosilica, meanwhile, make it a promising material for use in other areas such as microelectronics and medical implant materials.
From sponge skeleton to microchips. It is an incredible journey through space and time. From the prehistoric depths of the sea, a brave new world is indeed arising.